1. Field of the Invention
The present invention relates to a network game system in which a game is played among a plurality of players.
2. Description of the Related Art
The recent advancement of network technology promotes expansion of a network game (online game) which is played among a plurality of players. A system for a network game includes a server apparatus that is managed by an operator of a network game, and client apparatuses of individual players that are connectable to the server apparatus through a network, such as Internet.
In the network game, a player inputs an instruction with respect to a player character from an input device in a client apparatus, such as a video game apparatus, and accordingly plays the game. The network game does not allow only one player to play the game. That is, player characters of other players appear while the game is being played. Another network game is also known in which non-player characters, not player characters of players, appear while the game is being played. The non-player characters must take the same actions in the client apparatuses of the individual players.
The actions of player characters of a plurality of players or the actions of non-player characters must be noticed to the client apparatuses of the players so as to be consistent. For this reason, in the known network game, instructions regarding the actions of the player characters are collected into the server apparatus from all the client apparatuses, and the server apparatus collectively performs a processing necessary for the progress of the game, such as decision of the actions of the non-player characters. Information based on the processing result is distributed to the client apparatuses (for example, see JP-A-2003-325984 (Paragraphs 0059 and 0060)).
As in Patent Document 1, however, if the server apparatus must collectively perform the processing for the progress of the game, a lot of processing load is imposed on the server apparatus. In particular, in case of a game in which the actions of a plurality of player characters interact with each other on the progress of the game, as the number of player increases, the computation amount of processing of the server apparatus increases two or more times.
If the actions of the player characters affect the actions of the non-player characters or if the actions of the non-player characters affect the actions of the player character or other non-player characters, the computation amount significantly increases with respect to the number of characters. In order to solve this problem, the processing capability of the server apparatus may be increased, or the number of player characters or non-player characters may be limited. In the former case, an increase in cost may be caused, and in the latter case, an interest in the network game may be lost.
In general, an unspecified number of players enter the network game, and from among the players who play the network game, there may exist an unauthorized person who accesses the server apparatus and commits corruption. Presence of such an unauthorized person causes trouble to many other players. In order to allow many people to enjoy the game, it is necessary to quickly exclude a person who commits corruption. For the operator of the network game, management cost for exclusion of a person who commits corruption is no small matter.